Direction of oxidation-reduction reactions which of the following reactions would you expect to proceed in the direction shown, under standard conditions, in the presence of the appropriate enzymes? (a) malate + nad+ oxaloacetate + nadh + h+ (b) acetoacetate + nadh + h+ β-hydroxybutyrate + nad+ (c) pyruvate + nadh + h+-lactate + nad' (d) pyruvate + β-hydroxybutyrate-→ lactate + acetoacetate (e) malate + pyruvate (f) acetaldehyde+ succinate-→ ethanol + fumarate → oxaloacetate + lactate